fn main() {
    let decimal = 65.32_f32;
    let i = decimal as u8;
    let c = i as char;
    println!("{}", decimal); //65.32
    println!("{}", i); //65
    println!("{}", c); //A
    println!("1000 as u16 = {}", 1000 as u16); //1000
    // println!("1000 as u8 = {}", 1000 as u8); //错误，溢出
}
